"Chimera" mice grown with livers made of human cells are the ultimate test bed for new liver drugs, say scientists. Already, bio geeks have been growing mice with human brain cells, so this liver stuff is just icing on the genetic cake. [Salk Institute]

A new study shows that the more manly you are, the more likely you are to want to punish immigrants. I think this explains a lot about certain episodes of Battlestar Galactica. [Eurekalert] Why bugs love rough sex after the jump.

Insects love violent sex, often inflicting lots of wounds during the insemination process. Now scientists know it's not because there's a sadomasochistic sex gene that we've inherited from bugs. Instead, it's because female insects need to have their immune systems activated when sperm enter them, in order to get rid of pathogens that might get inside along with all that desirable bug spunk. [Science Blog]